Case Study

Boost Japanese Sales: SiteLocaleAI Case Study

Published April 26, 2026

Boosting Japanese E‑Commerce with SiteLocaleAI

Published on SiteLocaleAI Blog – 2026‑04‑26

Overview

When Kira Boutique, a fashion e‑commerce store based in Berlin, decided to enter the Japanese market, they faced three classic challenges:

Accurate price conversion – raw exchange rates often produce awkward numbers (e.g., ¥12 345). 2. Psychological pricing – Japanese shoppers respond better to prices ending in 99 ¥ or 0 ¥. 3. Search‑engine visibility – Google and Yahoo Japan index only the language they crawl; untranslated pages stay invisible.

Using SiteLocaleAI’s drop‑in JavaScript library and SEO CLI, Kira Boutique localized prices with charm rounding, delivered fully translated pages to crawlers, and kept everything on‑premise using their own LLM API keys. The result? A 38 % increase in conversion and a 25 % reduction in bounce rate within the first two months.

Why SiteLocaleAI?

Framework‑agnostic – works with React, Vue, WordPress, Shopify, or a plain HTML site.
Self‑hosted – you supply your own LLM keys (Claude, GPT‑4o‑mini, etc.), keeping data private and costs predictable.
Price localization – built‑in psychological rounding per currency.
SEO pre‑rendering CLI – generates static, translated HTML for crawlers.
WordPress plugin – no Node.js required for non‑technical teams.

All of these features aligned perfectly with Kira Boutique’s tech stack, which runs a static site generator (Eleventy) and a small Node.js backend for checkout.

Implementation Steps

1. Install the library

npm install @sitelocaleai/js

Or, for a pure‑HTML site, add the CDN script:

<script src="https://cdn.sitelocaleai.com/v1/sitelocaleai.min.js"></script>

2. Initialize with your LLM key

// src/localization.js
import SiteLocaleAI from '@sitelocaleai/js'

const locale = new SiteLocaleAI({
  apiKey: process.env.CLAUDE_API_KEY, // or GPT‑4o‑mini key
  targetLang: 'ja',
  currency: 'JPY',
  rounding: 'charm' // <-- enables 99‑yen ending
})

export default locale

3. Wrap price elements

<span class="price" data-price-usd="49.99">$49.99</span>

// src/main.js
import locale from './localization.js'

locale.localizePrices('.price')
  .then(() => console.log('Prices localized for Japan'))
  .catch(console.error)

The library fetches the current USD‑JPY rate, applies psychological rounding (e.g., ¥5 499 → ¥5 499) and updates the DOM:

<span class="price" data-price-usd="49.99">¥5 499</span>

4. Translate page content

locale.translatePage('ja')
  .then(() => console.log('Page translated'))
  .catch(console.error)

All text nodes are sent to the configured LLM, preserving brand tone while adapting idioms for Japanese shoppers.

5. SEO pre‑rendering

SiteLocaleAI ships a CLI that crawls your site, runs translations, and writes static HTML files. Run it before each deployment:

npx sitelocaleai seo --lang ja --output ./dist/ja

Search engines now see a fully translated version at https://kira‑boutique.com/ja/, improving indexability and ranking.

Measurable Impact

Metric	Before Japan Launch	After 2 Months	% Change
Conversion rate	1.8 %	2.5 %	+38 %
Avg. order value (JPY)	¥7 200	¥7 800	+8 %
Bounce rate	62 %	46 %	‑25 %
Organic traffic (Japan)	1 200 visits/mo	2 100 visits/mo	+75 %

The biggest driver was the price‑rounding algorithm. Japanese shoppers are accustomed to “charm prices” (e.g., ¥5 499) that feel like a deal without being too low. By automating this per currency, Kira Boutique avoided manual spreadsheet work and eliminated pricing errors.

Lessons Learned

Cache exchange rates – the LLM call is cheap, but fetching rates for every page hit adds latency. Cache the rate for at least 30 minutes.
Hybrid translation – combine LLM output with a small glossary for brand‑specific terms (e.g., “Kira” stays unchanged). This reduces post‑editing time.
Test rounding thresholds – what works for JPY may differ for KRW or THB. Use the rounding option (charm, floor, ceil) to experiment.
Leverage the CLI for sitemaps – the CLI automatically updates sitemap.xml with the new language paths, ensuring Google Search Console picks them up quickly.

How to Get Started

Sign up for a free trial at SiteLocaleAI.com.
Follow the quick‑start guide to add the script to your site.
Enable price localization with the rounding: 'charm' option as shown above.
Run the SEO pre‑render CLI before each release.

For deeper technical details, see the price‑localization docs.

Ready to Expand Globally?

If you’re an e‑commerce brand looking to replicate Kira Boutique’s success in Japan—or any other market—SiteLocaleAI gives you the tools to translate, price, and rank without sacrificing data privacy or performance.

Try SiteLocaleAI today and watch your international conversions soar! 🚀

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